Why don't we try to write our own firmware??
 

Hi

Looking for mp4 firmware upgrades i've founded that there are always problems with them. I'm new in this forum and i don't know yet whether there is already a proposal to write our own firmware. Altough it seems a heavy task, when sharing it with hundreds of programmers it becomes an easy duty. In the web there are schematics and datasheets of the circuits used in the mp4 gadgets.

I'm electronic engineer and i have experience programming 8 bit microcontrollers and dsp's (there is a Z80 inside an mp4 "atj2085"). I'm shure there are a lot of brillant people here, so the question has been opened =)

In the long run it would be a futile effort. There are so many different players, so many different firmware types and versions for too many chips and boards. You would have to write literally hundreds if not thousands of different firmware types for players that are constantly changing in specs. Something i wouldn't want to do.

If someone bricks thier player due to flashing incorrect firmware, thats thier fault. Why waste time writing firmware that only going to be compatible in a handful of players at any given time?

There's swan project which aims to deliver open source super customizable firmware: http://wiki.s1mp3.org/index.php/Swan_Project
But there's not much progress. You can read mailing lists if you are interested: http://lists.s1mp3.org/pipermail/s1mp3-dev/

Actually all the players i've seen 'til now are based in the ATJ20xx mpu, including those that only plays mp3 (usb dongle). That means that having written the core code it is only a matter of modifying certains lines in the code (and then compile it) to made it available for other models (hw core doesn't change drastically). Think about this: although there are dozens of brands that manufacturer handhelds (eg PALM) all of them are using the PalmOs operating system, so if you are gonna compile for one brand then you do something like this

#include ".\os\clie.h"

but for another brand you use this instead:

#include ".\os\palmspring.h"

and so on.

That is, no matter which brand you are using, all of them are based in the same mpu, an ARM 32 bit. With this gadgets is the same, all of them has inside some member of the ATJ20xx family. Even we may standarized some firmaware and track them in any moment.

Whar do you guys think?? =)

I think you should think about joining the s1mp3.org team they are already doing it

Re: Why don't we try to write our own firmware??
 

Hi

Thanks for your interest in the topic. I'm embedded system programmer, which means I have the skills and knowledge for programming this kind of stuff, although, however, we need to set up several things before we can start. Among other things i'm writting an open-platform real time kernel that we may use.

As i've read so far there is a Z80 mpu inside the ATJ20xx, but there is also a DSP (i programm dsp as well). The first thing we must do is to get the tools for compiling and downloading programms into the atj. Once done we'll be on the road to do anything we want. I guess there are C free compilers for the Z80, and the JTAG interface is not hard to build a home-made one. There are free tools to download the image to the mp4, so it's just a matter of getting all this stuff together to start with.

As far as i read in s1mp3.org there is not such a project =( (they want to make reverse engineering)

Re: Why don't we try to write our own firmware??
 

This may help, information about the Z80 CPU:
http://www.zophar.net/tech/files/z80_faq.html

Re: Why don't we try to write our own firmware??
 

Lets begin from the begining.
Programs for flash memory:
http://www.samsung.com/Products/Semi....htm#nandflash
Most used memories:
http://www.hynix.com/eng/02_products/03_flash/index.jsp
http://www.micron.com/products/nand/
http://www.samsung.com/Products/Semi...lash/index.htm

I have absolutely no knowlege about programming, but I can be of help by testing your firmware with my MP4 player, it's a 220x176 pixels 1GB atj2093 with 3.6v battery... good luck with your project, I can also do stuff for the interface (in photoshop/paint), I doubt it will be very original though...

Testing new firmware will be very dangerous for the first time.
So I purpose to post your contacts down here if you would like to test new programs for your player.
Testing firmware will be not so soon as you think.
Write down information about your player (screen size, memory, resolution), information about your PC (Operating system - Windows, Linux etc.) & contact information (Use some bug - for example mail adress Mail%mail.ua to prevent a spam)